Youths jeered and jostled France's interior minister Tuesday in the northern city of Amiens when he promised to restore law and order at the scene of overnight riots in which police were fired at with buckshot and pelted with missiles.
President Fran莽is Hollande said the state would "mobilize all its resources to combat this violence," which has shaken depressed quarters of major French cities at regular intervals over the past decade.
Police and emergency officials in Amiens are on high alert and some, speaking on condition of anonymity, said they feared a further flareup of violence.
Unrest is often blamed on a combination of poor job prospects, racial discrimination, a widespread sense of alienation from mainstream society and perceived hostile policing.
A crowd of about 100 young men met Interior Minister Manuel Valls when he arrived in Amiens to discuss two nights of violence apparently sparked by tension over spot police checks on residents.
"Calm down! Calm down!" Valls yelled as the crowd jostled him while he entered the town hall surrounded by bodyguards.
Valls said 17 police officers were hurt in the rioting, some hit by shotgun pellets, others by a hail of objects thrown by around 100 youths gathered in the city's northern districts.
"Firearms! Can it be considered normal that people turn firearms on police? It's unacceptable ... law and order must be restored," Valls told a news conference, adding that a minority of people were terrorizing the local community.
One officer was in serious condition, the city's Socialist Mayor Gilles Demailly told Reuters.
Hollande, who ordered Valls to break off their joint visit to southeastern France and travel to Amiens, said too little money had been put into security.
"Our priority is security which means that the next budget will include additional resources for the gendarmerie and the police," he said.
The unrest was the first major law and order test for Hollande's Socialists since his May election victory over conservative incumbent Nicolas Sarkozy, whose tough policies on crime and immigration some critics said fanned urban unrest.
Ahmed, a 27-year-old jobless man who refused to give his family name, revealed the sense of anger some locals felt.
"Yesterday our little brothers did a good job," he said. "Imagine if we got involved, then it would get serious. It's a shame nobody got killed yesterday."
The Interior Ministry sent reinforcements to Amiens, part of which was already classified as a "priority security zone" in need of extra policing. The policy formed part of the Socialists' election campaign pledge on law and order.
Riot police and gendarmes sat in two dozen vans parked in the northern neighbourhood where a recent face-lift included the building of a gymnasium, swimming pool and cultural centre.
One resident, a taxi driver who gave his first name as Jonathan, called the perpetrators "a bunch of idiots."
"It's a game for them and will happen again. It's just to cause trouble, because they are hurting their own people," he said, blaming the riot on weak policing in recent years.
"It was a 'no man's land' and now they want to put in a big police presence. That will only provoke them," he said.
The immediate cause of the two days of disturbances appeared to have been a police spot check on Sunday on a person on the sidelines of a funeral of a young man killed in a road accident.
During a night of violence, rioters set fire to a number of vehicles, in some cases hauling the drivers out of their cars.
